I have recently got a new HSD ES929 Spindle and Altivar 71 VFD. At the moment every thing seem to be running fine except that any time I try to lower the "Low speed" frequency past 60Hz/2000RPM it looks as if it is pulling to many Amps and faults out the VFD. HSD says that there should be no issue running this spindle all the way to 0RPM. We normaly run it around 800RPM when useing drill bits. Also when the spindle is running around 2000RPM it makes a noise that does not sound good, after around 5000RPM the noise goes away completely. If anyone can help me fine tune this it would be greatly appreciated.

Altivar 71
11kW - 15 hp
220v 3 phase

HSD ES929
7.5 kW - 10 hp
220v
27.4 Amps
800 Hz
24000 RPM